RFI (rec. 5.06.26) 2567 - Appendix B - Site-Based Stormwater Management Plan (SBSMP) (Ver. 2)

5.0 FLOODING

The subject site is not shown to be impacted by regional flooding. Flood mapping from Noosa
Shire Council Disaster Management Mapping (see Figure 5-1) shows that there is no flood
encumbrance for this site. Noosa Shire Council has confirmed that no modelling or historical
flood data is available for this site (see Appendix F).


The site is situated at the high point of the local catchment. The terrain data indicates a 1m
high constructed berm along the western and southern boundaries, each containing a swale
that extends north and west, respectively. These swales average 5 meters in width and 0.3
meters in depth, with a longitudinal grade of 1%. Each swale has a flow capacity of 0.9 m³/s,
resulting in a total combined capacity of 1.8 m³/s (see Appendix E for swale capacity
calculations).


This capacity is equivalent to the runoff generated by 1 Ha of pervious land in each direction.
The upstream catchment area draining to these swales is conservatively estimated at up to
1.2 Ha of pervious surface. Therefore, the swales provide more than sufficient capacity to
convey flows from the upstream catchment, with adequate freeboard provided by the bund.




            Figure 5-1 Extents of various flood events from Noosa Shire Council Disaster Management Mapping



2576-SBSMP-01_Version 2.0 (April 2026)                                                                   Page 21 of 23
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